Gaseous electric discharge device



Dec. 9, 1941.

M. REGER GASEOUS ELECTRIC DISCHARGE DEVICE Filed Au 31, 1938 INVENTOR Mari 'L'n Reger BY W011i fiamzum ORNEY Patented Dec. 9, 1941 GASEOUS ELECTRIC DISCHARGE DEVICE Martin Reger, Berlin-Charlottenburg, Germany,

assignmto General Electric Company, a corporation of New York Application August 31, 1938, Serial No. 227,831 In Germany September 18, 1937 3 Claims. (Cl. 176-122) The present invention relates to gaseous electric discharge devices generally and more particularly the invention relates to such devices of the high vapor pressure type having a starting gas and a quantity of mercury therein which is wholly vaporized during the operation of the device;

Such devices require a series resistance to stablize the discharge therein and choke coils and condensers have been preferred for this purpose since these types of resistances consume very little electric energy, if any. Such wattless resistances are expensive and, because of their size, must be mounted separate from the lamp device.

It is desirable to incorporate the series resistance in the structure of a lighting device to constitute a self contained unit which can be connected into the ordinary light socket without the need for any external auxiliary equipment. For this purpose a discharge lamp has been mounted together with a series connected ohmic resistance, in the form of an incandescent filament, in a sealed bulb so that th electrical energy dissipated in the series resistance is converted thereby into light and heat to improve the overall efliciency of the electric lamp. To obtain the maximum light output from the filament it must be made relatively small and, indeed, of such dimensions that, during the operation of the lamp device, it dissipates about 25 to 30% of the supply voltage. I have observed that a resistance of such size is satisfactory for ballasting the discharge lamp only when the line voltage is constant since, with a fluctuating line voltage, either the filament is overloaded and isshort lived or the electrodes of the device are not maintained at a-discharge supporting temperature and the discharge lamp is extinguished. due to changes in current in the lamp device. For example, an increase of 5% in the line voltage, when the filament is of such size that it dissipates about 25% of the line voltage, causes a voltage increase of at least 20% across the filament.

The object of the present invention is to prov de a lighting device of the above type which is highly eflicient and in which the above disadvantages are avoided. Still further objects and advantages attaching to the device and to its use andoperation will be apparent to those skilled The iron wire 7 type which is heated to incandescence during the operation and is mounted in a bulb containing a mixture of argon and nitrogen about 30 to of the line voltage must be dissipated in the resistance to assure successful operation of the lamp on a fluctuating line voltage. The series resistance in a lamp embodying the present invention, however, need dissipate only 20% or less of the line voltage because the iron wire in an 7 atmosphere of hydrogen or helium has a very steeply rising volt-ampere characteristic and is, therefore, eminently satisfactory for preventing harmful current changes when the-line voltage fluctuates.

When of the electric energy consumed by the electric lamp is converted into light by the arc discharge the gain in efliciency of the discharge device more than compensates for the loss of the light emitted by the series incandescent filament of prior devices as will be apparent from the following example:

When the discharge device and the incandescent filament are so dimensioned that the lamp device operates on 220-volts and the filament dissipates volts the efliciency of the filament is 1'7 lumens per watt and the efliciency of the dischargedevice is 3'7 lumens per watt. The overall efliciency of the lamp device is thus 2'7 lumens per watt. When the operating voltage of the discharge device is volts, in accordance with the 4 it is desirable that the reignition voltage on eachhalf cycle does not exceed the operating voltage by more than 20%. This can be assured by providing auxiliary, starting electrodes in the discharge device.

During the starting period of the lamp it is desirable to connect a second resistor in series with the iron wire in order to control the starting current. When the discharge device is at operating equilibrium. the starting resistance is short-circuited by a third resistor having a negative temperature coefiicient of electrical resistance connected in parallel with said starting resistance. Preferably the resistor having a negative temperature coefficient of electrical resistance is mounted in heat receiving relation to th discharge device whereby heat generated therein causes its resistance to be reduced during the operation of the device.

In the drawing accompanying and forming part of this specification an embodiment of the invention is shown in a front elevational, partly sectional view.

aaeaaee v v visible light to complement and supplement the Referring te-the drawing the electric lamp comprises a spherical, sealed bulb I of vitreous material, such as glass, having a gaseous electric discharge lamp device mounted therein. The discharge device comprises a tubular container 2 consisting of a vitreous material having a high softening temperature, such as hard glass or quartz, and having therein a starting gas, such as argon or neon, or a mixture thereof, at a-pressure of about 10 mm. to a few centimeters and a quantity of mercury in such an amount that it is completely vaporized during the operation of the device and produces a vapor pressure such that the operating voltage of the device is about 80% of the line voltage. A vapor pressure of about three atmospheres is desirable for this purpose.

Current leads 5 are fused into the protuberances 4 at each end of the container 2 and thermionic, activated electrodes 6 are mounted on the inner ends of said current leads 5. Preferably, each of said electrodes 6 consists of a tungsten wire helix wrapped around a pellet of material having high electron emissivity, such as barium oxide. An auxiliary electrode 1 is mounted in said container 2 adjacent each of said electrodes 6. Each of said auxiliary electrodes I is connected in series with a high ohmic resistance 8 to the current lead 5 of the electrode 6 opposite to that electrode Ii .to which said auxiliary electrode I is adjacent. Said auxiliary electrodes I facilitate the starting of the main arc discharge between said electrodes 6 and reduces to .a minimum the diilerence between the reignition voltage and the operating voltage of the discharge. The gaseous electric discharge device is supported in said bulb l by the current leads 9 and I fusedinto the press l3 of the stem of said bulb I Said leads 9 and Ill are connected to the leads 4 of the discharge device and the contacts on a base (not shownfor purposes of simplicity) fastened to the bulb I. When desired, an ohmic resistance l for controlling the starting current of the lamp is mounted in the base and a resistance It having a operation of the lamp. When desired these elements are mounted in the bulb I in heat receiving relation to the discharge device or the shortcircuiting resistance alone is mounted in said bulb I.

A resistance I I consisting of iron wire is mounted insaid bulb I on the support wires I2 and is concentric with the container 2 of the discharge device. Said resistance II is connected in series with said discharge device. The bulb I is filled with helium or hydrogen which gives the resistance I I a very steeply rising positive volt-ampere characteristic.

When desired-the discharge device is enclosed by an hermetically sealed, light transmitting vitreous envelope mounted in the bulb I which enlight emitted by said device and to increase the efliciency of the lamp. when the .lamp device is intended for use as an ultra-violet generator the outer bulb I is made of a material which transmits these rays.

While I have shown and described and have pointed out in the annexed claims certain novel features of the invention, it will be understood that various omissions, substitutions and changes in the forms and details of the device illustrated and in its use and operation may be made by those skilled in the art without departing from the broad spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. An electric lamp comprising in combination an hermetically sealed bulb, a gaseous electric discharge lamp mounted in said bulb and con-' taining a quantity of vaporizable metal which is wholly vaporized during operation of the device, a resistor mounted in the space between said discharge lamp and said bulb, said resistor being an iron wire connected in series with said discharge lamp and being of suchsize that when operating below light-emitting temperature it dissipates less than 20% of the voltage normally consumed by said electric lamp, said bulb containing a gas from the'group consisting of helium and hydrogen, a starting resistor initially connected in series with said iron wire resistor and means for automatically short-circuiting said starting resistor when said lamp is at operating equilibrium.

2. An electric lamp comprising in combination an hermetically sealed bulb, a gaseous electric discharge lamp mounted in said bulb and containing a quantity of vaporizable metal which is wholly vaporized during operation of the device, a resistance mounted in the space between said discharge lamp and said bulb, said resistance being an iron wire connected in series with said discharge lamp and being of such size that it dissipates less than 20% of the voltage normally consumed by said electric lamp, said bulb containing a gas from the group consisting of helium and hydrogen, a starting resistance connected in series with said iron wire during the starting of said electric lamp and means to short circuit said last named resistance in response to heat generated during the operation of the lamp.

3. An electric lamp comprising the combination of a sealed envelope, a charge of gas therein from the group consisting of helium and hydrogen, an electric discharge device mounted in said envelope, said device containing thermionicelectrodes, a charge of rare gas and mercury of such quantity that it is wholly vaporized during operation of said device, an iron wire resistance mounted in series with said device in heat-re ceiving relation thereto within said envelope, said wire being proportioned to dissipate whenoperating at a temperature below light-emissive temperatures less than 20 per cent of the total voltage MARTIN REGER. 

